Device for signal purposes



Dc. 4, 1934, H, EISENHUT 1,983,356

DEVICE FOR SIGNAL PURPOSES Filed Oct. 31, 1.931

In venior:

' fly JWM Patented Dec. 4, 1934 UNITED STATES DEVICE FOR SIGNAL PURPOSES Hugo Eisenhut, Jena, Germany, assignor to Carl Zeiss, Jena, Germany Application October 31, 1931, Serial No. 572,357 In Germany November 6, 1930 1 Claim.

I have filed an application in Germany, November 6, 1930.

The present invention, which has reference to devices emitting directed light for signal pur- 5 poses, concerns optical telegraphy and the transmission of light signals to running trains and the like. With a View to increase the safety of working these devices have been provided with a spare light source which in most cases switches on automatically as soon as the principal light source discontinues working. In order to have the spare light source provide exactly the same ray path, generally the light sources themselves are movable. It also has been suggested for instance to fixedly provide the light sources and to use movable reflector surfaces which, when required, can be placed into the ray path.

Especially such instruments are concerned in this case which provide intermittent light by means of a rotating interrupting disc extending into the ray path. Intermittent signalling light is frequently used for preventing disturbances the transmission of signals would have to sufier on account of other sources of light, for instance day light. This prevention is not diiflcult at all when intermittent light is used.

According to the invention, a simple and convenient device for automatically interposing a spare source of light in the ray path is obtained 3 by constructing as a reflector, at least that part of the said disc which extends into the ray path, and by providing that the rays coming from one light source pass through the apertures in the interrupting disc from the non-reflecting side of 0 the disc and are inclined towards the plane of the disc and that the light rays coming from the other light source are reflected by the reflecting side of the disc into the direction of the rays emanating from the first said light source.

In this way the invention avoids any additional apparatus which, at least outside the device, in most cases equalizes the ray paths of each of the two light sources, and any loss of light worth mentioning is not to be noticed with either light source.

In the accompanying drawing, which illustrates schematically a constructional example of a device according to the invention, Figure 1 is a front elevation and Figure 2 a top plan view. Figure 2 shows also the electric connection of the sources of light.

The device according to the drawing comprises an incandescent lamp a the filament a of which is provided in the focus of a converging lens I) so that a light pencil A of parallel rays emanates from this lens. Into this pencil extends a toothed interrupting disc 0 the plane of which is inclined towards the pencil A by 45 and which is rotatable about a horizontal axis B. By means of this disc the current of light emanating from the lamp a and traversing the lens b is transformed into an intermittent one. On that side which is turned away from the lamp a the teeth of the disc 0, which are denominated 0 are provided with a reflecting layer. This side of the disc 0 is coordinated to a second incandescent lamp d the filament d of which is in the focus of a converging lens e. The axis of this converging lens is horizontal and intersects at right angles that of the pencil A, the consequence being that a light pencil emanating from the lamp d is so reflected by the reflecting layer of the disc 0 that it takes the same direction as the pencil A and is interrupted in like manner. The lamp a is connected by means of a solenoid f and a hand switch g to a battery h. The solenoid f contains an armature I This armature is drawn into the solenoid when this solenoid is traversed by current. Opposite the armature f are two contacts I and f which are interconnected by the armature when the solenoid is currentless and drops the armature. The contacts f and f are in the circuit of the lamp d, which is also connected to the battery h by means of the switch 9.

Accordingly, the lamp a burns when the device is connected by means of the switch 9. The current flowing to this lamp traverses the solenoid f, as a consequence of which the armature f is attracted and the circuit of the lamp d is interrupted. If the lamp a fails for a certain reason, for instance on account of a fusing of the incandescent filament a the armature f drops and closes the circuit of the lamp d, which is thus made to substitute the lamp a.

I claim:

A device for signal purposes emitting intermittent light, comprising a rotating disc having at its circumference equally spaced, radially extending transparent parts interrupted by nontransparent parts, the non-transparent parts being reflective at the one side of the disc, two light sources, means for normally energizing one of these light sources, means for energizing the other light source on the failure of the first light source whereby the intermittent flashing of the rays is continued by the second light source upon failure of the first light source, a lens system for each light source, each lens system directing the rays from the corresponding light source into a corresponding substantially parallel pencil, the one light source and the appertaining lens system being so disposed at the reflecting side of the nontransparent parts that the axis of this system intersects the said radially extending portions of the disc at an acute angle, and the other light source and the appertaining lens system being so disposed behind the disc that the axis of this system coincides with what is deflected of the optical axis of the lens system of the first said light source. HUGO EISENHUT. 

